In many instances where an object is fabricated from several components, there is a need for the points of juncture of the components to be sealed in order to provide the area enclosed by the components with protection, for instance, from penetration by the elements. Such sealing needs are, for instance, exemplified in the case of vehicles by a need to seal the juncture between the doors, trunk lids, and hoods, and the enclosed spaces associated therewith. Such sealing is typically accomplished by the presence of profile strips that include a relatively soft portion, which forms the weatherproof seal, and a harder portion, which serves as a carrier for the sealing portion. The carrier portion is commonly provided with a channel formed between two opposed walls connected by a base, designed to accept the insertion of the flange fabricated, for instance, from the sheet metal used to form the vehicles, the flange being located around the enclosed space to be protected.
The method for attaching such profiles involves the placement of the profile channel over the flange, the profile being retained by the frictional force of the channel walls against the flange. In most instances, finger-like projections extend from the opposed walls which frictionally engage the flange, further enhancing resistance to removal of the profile therefrom. When positioned as described, the sealing portion of the profile, which extends from a carrier portion, is desirably held in a sealing position.
While the installation of profiles of the type referred to is readily accomplished, the continual forces applied to the profiles as a consequence of the repeated opening and closing of the doors, trunk lids, hoods and the like have a tendency, especially in warm weather, to gradually loosen from the flanges on which they are mounted even when the profiles are provided with flange-engaging fingers, such loosening often leading to separation from the flanges.
As a consequence of the foregoing, weatherstrip profiles of the type described are commonly fabricated with reinforcement, for example, with reinforcing metal or equivalent material embedded or encased in the carrier. This type of construction, together with the use of dense rubber employed in forming the channel is designed to improve the gripping action of the channel on the flange over which the channel is positioned. However, while the reinforcement-containing carriers are normally available in a range of configurations and sizes that can be individually designed to provide both the required retention and sealing functionality, such devices nevertheless have certain inherent disadvantages that are difficult to avoid.
Among these disadvantages may be mentioned the extra cost of fabricating reinforced sealing profiles, including the cost of the added operations required for their fabrication compared to unreinforced profiles, as well as the cost of the additional inventory involved. Also profiles extruded with reinforcing wire tend to protrude slightly at the wire locations, resulting in an unsightly series of raised ribs. Furthermore, sealing profiles are difficult to install around small radius corners without buckling or wrinkling, an effect giving rise to sealing leaks. In addition, when the channel walls of the sealing are parallel to, or divergent from each other, the profiles have an unfortunate tendency to spread apart as they traverse the corners of flanges on which they are mounted. This necessarily results in a decrease in the frictional force with which the walls or fingers grip the flanges, thus increasing their tendency to become separated from flanges on which they are mounted.
A still further disadvantage of wire-reinforced profile seals resides in the fact that they cannot be shaped longitudinally by curved extrusion technology as disclosed in U.S. Pat. No. 4,906,171 and U.S. Pat. No. 5,069,853, nor can extrusion dies be changed rapidly as described in U.S. Pat. No. 5,067,885.
In view of the preceding, therefore, it is a first aspect of this invention to provide an improved weatherstrip seal profile.
A second aspect of the this invention is to provide weatherstrip seals that require less rubber to make and thus are less expensive to produce than many of those of the prior art.
Another aspect of this invention is to provide heat-set weatherstrip seal profiles that have the ability to traverse relatively small radii without wrinkling or buckling.
Another aspect of this invention is to provide unreinforced weatherstrip seals that can be anchored as securely to the mounting flanges with which they are associated as weatherstrip seals that are fabricated with encased reinforcement.
A further aspect of this invention is to provide weatherstrip seals characterized by their ability to grip flanges on which they are mounted more securely in areas of flange curvature.
An additional aspect of this invention is to provide weatherstrip seals that include carriers that have no reinforcement, particularly metal reinforcement therein, thereby providing a cost savings over seals of the prior art.
A still further aspect of this invention is to provide weatherstrip profiles with a smoother and more attractive appearance by elimination of wire reinforcement therefrom.
Another aspect of this invention is to provide profiles unreinforced with wire adapted to fabrication by methods capable of employing corner extrusion technology and rapid die change procedures.
Yet another aspect of this invention is to provide a weatherstrip profile that can be heat-set in the configuration required for installation on a particular mounting flange.